Swing joint



May 21, 1946.

` A. v G. SHEPHERD SWING JQIN T Filed Spt. 17,. 1943 Inventor Allan G. Shepherd- Atjeni Patented May2l, 1946 `Allan G. Shepherd, Burbank, Calif., assigner, by

mesne assignments, to Lockheed Aircraft Corporation, a corporation of California Application September, 1943, Serial No. 502,791

6 Claims.

This invention relates to iiuid conducting joints,

and relates more particularly to swivel joints or swing joints for embodiment in systems and mechanisms handling iluid under pressure. A

general object of the invention is to provide a simple, practical and highly effective -iiuid conducting swing joint.

In many iluid pressure systems it is necessary or desirable to employ swivel joints or swingk joints. For example, this type of joint is extensively employed in fluid systems in combination with rigid tubing instead of the flexible hoses heretofore employed in such situations. So far as I am aware, none of the swing joints that have been introduced are hydraulically balanced. As

.a result of the unbalanced uid pressure conditions in the prior joints, there is considerable frictonal resistance to relative rotation between the joint'parts, and in vsom'e types of joints the sealing material is subjected to unbalanced and excessivev pressures. These conditions are aggravated, and the resistance to relative rotation between the parts is materially increased,`.in installations where the fluid is handled under high pressures. In many of the prior swing joints the sealing material is actuated or compressed by screw threaded parts, springs, or the like, and offers substantial resistance to relative rotation of the parts even under low uid pressure conditions. Further the conventional swing joints are usually quite expensive and often embody antifriction bearings for assuming the loads which result from the unbalanced pressure conditions.

A principal object of this invention is to provide a swing joint for handling iluid under pressure in which the relatively rotatable elements are hydraulically balanced to allow free relative rotation under all fluid pressure conditions. The torque required to swing or rotate the movable joint element is exceedingly small and does 'not change appreciably with increase or decrease in the uid pressure.

Another object of the invention is to provide `a swing joint that does not embody or require screw lthread means, or the like, for conditioning or compressing the sealing means. In the joint of thepresent invention, the sealing rings are merely engaged in grooves in one or both of the relatively turnable Joint parts under suitable initial diametrical compression to seal between said parts and no compressing or actuating means are the only other elements employedare sealing rings and a washer.

Other objects and features of this invention will become apparent from the following detailed description of a typical preferred form of the invention throughout which description reference may ce had to the accompanying drawing in which: 1

Figure 1 is a side elevation of the joint of the invention;

vFigure 2 is a central longitudinal detailed secy tional view of a joint of the invention; and

Figure 3 isa'transverse detailed sectional view taken as indicated by line 3-3 on Figure 2.

. The present invention may be embodied in joints varying considerably and having different applications. In the 'drawing I have illustrated one simple form of the invention constructed to handle a single stream ofy iluid under pressure.'

It is to be understood that the invention may be embodied in forms suitable for other uses' and the invention is not to .be taken as limited to n the purely illustrative embodiment herein described.

The swing joint of the present invention may be said to comprise generally a body I0, a sleeve member II, the body and member being related for relative rotation, and meanskl2 for sealing between the body and member.

The body I0 forms the inner part and principal element of the joint assembly. In the simple form of the invention illustrated, the body I0 is a one-piece element resembling a stud or bolt. The body I0 is formed or provided at its inner end with means for facilitating its connection with a part'l I3 of the uicl handling system or apparatus. I have shown the body I 0 provided with',

an externally screw threaded stem I4, threadedly engaged in a uid opening I5 in the part I3. The part I8 has a boss I6 through which the opening I5' extends and the stem I4 is screwed into the boss. The stem I4 is of reduced external diameter providing the body AIII with an annular shoulder I1 which opposes the end face of the boss I6.

" The exterior of the body I0 is stepped or grad" uated between the shoulder I1 and the stern I4 to have a second annular shoulder I8. The second shoulder I8 may be relatively narrow and sloped downwardly and inwardly. 4A suitable sealing ring I9 is arranged around the stem I4 and is compressed between the shoulder I 8 and the end of the boss I6 to prevent the leakage of uid under pressure from around the stem.

The body I II is an elongategenerally cylindrical .element and has a cylindrical external surface extending outwardly from the shoulder I1. The

Y outer end of the body I0 is provided with a radially projecting flange or head 20,. The inner or under side ofthe head 20 forms a face which is preferablyA at'and normal to the longitudinal -all times.

of the stem I4 into the opening I5.

In accordance with the invention, the body `III is rigidly secured to the part I3 by threading the stem |4 into the opening I5. The threading of the stem into the opening is definitely stopped or limited so that the inner -face of the head 20 bears a given spaced relation-to the face of the boss I6. A washer 2| is arranged around the stem I4 to be clamped between the body shoulder I1 and the end face of the boss I 6. When the stem I4 is threaded into the opening washer 2| becomes tightly clamped between the shoulder- I1 and the face of the boss I6. The washer 2| is larger in external diameter than the body I and presents a face which opposes the inner face of the head2!) and which bears a given spaced relation to the face of the head. It is to be understood that the washer 2| may be dispensed with if desired so that the body shoul- I5 the site sides oi' the annular groove 23 to prevent the leakage of fluid from between the body and member. The means I2 is characterized by the fact that it oiers little resistance to relative rotation between the body lli and member, and

by the fact that variations in the pressure en the fluid being handled do not appreciably vary the resistance to the relative rotation. The sealing means I 2' includes sealing rings 28 carried either by the body III or the memberII. In the particular construction illustrated, the sealing rings '28 are provided on the body I0 to seal with the internal surface of the member II. An annular external groove 29 is provided in the Abody I0 at each side of the groove 23 and contains a sealing ring 28. The grooves 29 are preferably equally spaced, from the groove 23. In the particular structure illustrated, the end walls of the grooves. 29 are flatv and normal to vthe longitudinal axis of the joint, it being understood that in some cases it may be desired to f chamfer or'round oi the corners occurring where der I1 directly cooperates with the boss I6, in

which case the boss I6 presents an end face having a given spaced relationto the inner face of the head 20. It is important to notethat the shoulder I1 or washer 2|, as the case may be, constitutes a stop for limiting the inward screwing Aof the stem I4 to assure the definitel yby the integralvend wall or headof the body.

An annular external groove 23 is provided in the body I0 and a plurality of spaced radial ports 24 extends from the passage 22 to the groove 23. The groove 23 is substantially midway between the inner face of the head 20 and the shoulder I1.

The member I I constitutes the outer element of the joint assembly. The member II is in the nature of a tube or vsleeve surrounding the body I9 between the head A2|! and the boss I6. 'I'he central longitudinal opening of the member I I is proportioned to receive the body III so that there may be free relative rotation between the body `and member. The opposite ends of the member I Ifare preferably, though not necessarily, fiat and normal to the longitudinal axis of the Joint. The

the walls of the grooves join the external surl face of the body., The sealing rings 28 are formed of flexible resilient sealing material such as rub- The rings 28 grooves 29 and the interior surface of the member II. This form ofv sealing ring has proven to l be vhighly eiective under high pressure conditions, varying temperature conditions and extensive usage. A substantial increase in the pressure on the iluid being handled will not cause the sealing rings 28 to oier any appreciable in crease in resistance to relative rotation between the body I0 and the member II. It is to be observed that the compression force which maintains the sealing rings 28 active, does not tend to urge the sleeve member II axially in either direction. In fact, the iluid pressures' acting on the member II and the sealing 'rings 28 are member II is proportioned to be readily received l between the inner face of the head 20 and the washer 2|. In practice, the length of the member I0 may be slightly less than the distance between the face of the -head 20 and the washer 2| so that the member remains free and cannot be bound when the stem I4 is screwed home in the opening I5.

The member II is formed to facilitateits con-4 nection in the iluidhandling system. A lateral or radial boss 25 projects from the member substantially midway between its ends. Ivhave shown the boss 25 externally screw threaded to readily receive a coupling or connection 26 of the fluid system. A iiuid opening or passage 21 extends through the boss 25 and wall of thel member II to communicate' with the groove 23. It is believed ,that it will be understood how the ports 24 and groove 25 maintain the passage 22 and the passage 21 in i'ull communication at The means I2 serves to seal between the body I II and the interior of the member II at oppobalanced, and the member I I is not urged against the head 20 or the washer 2| and there is no necessity for incorporating thrust bearing means in the joint.

-It is believed that the utility and practicability of the joint provided by the invention will be readily apparent from the foregoingv detailed description. With the joint connected to the part I3 and coupling 28 as illustrated, fluid under pressure may be conducted through the joint in either direction. The member II is free to turn or rotate with respect to the body I0 when the Joint carries iluid under pressure.' In this connection, it is to be observed that the hydraulic pressures on the joint are balanced so that they do not resist relative rotation between the joint parts. Assuming that the part I3 is relatively stationary and that the member II is turned with respect to the body I0, it will be seen that the i'luid pressure does not resist such turning and does not urge any of the parts into frictional therefore balanced out. Where the fluid is undery exceedingly high pressure. the sealing rings 28 may` be distorted to a minor degree so that they amants means for sealing between the bodyand member increased. In practice, however, the distortion of the rings 28 is very slight and the increase in the friction is minor, being much less than developed by other types of sealing means under similar circumstances. The groove 23 is annular and the zone between the rings 28 is annular and substantially unbroken so that the radially directed iluid pressures actin-g on the member il are substantially balanced. The .joint is inexpensive to manufactureand is easily installed and serviced. l

Having described only a typical form of the invention, I do not wish tobe limited to the specic details herein set forth, but wish to reserve to myself any variations or modifications'that may appear to those skilled in the art or fall within the scope of the following claims.

I claim:

1. A swing joint for use with a part having a t .rotation, the cooperation lof the iirst named shoulder and said face preventing the member from being clamped between said face and second shoulder, and means for sealing betweenv the body and member, there being a fluid passage 4'extending through the body and member and communicating with said uid opening.

2. A swing joint for use with a part having a fluid opening and a face, the joint comprising a body, a stem on the body adapted to be threaded into said opening to secure the body to said part, a shoulder. on the body extending inwardly from the external surface of said body for engaging said face to limit the threading of the stem in said opening, a second shoulder on the body extending outwardly from the external surface oi.' said body and opposing said face and bearing a definite spaced relation to said face by reason of the engagement of the nrst named shoulder with said face, a member freely rotatable on the body between said second shoulder and said face and installable-over the first named shoulder, the bodyI and member having a iluid passage communicating with said opening, and means for sealing between the body and member for preventing the leakage of uid therebetween.

3. A swing joint'for use with a. part having a iluid opening and a face, the Joint comprising a body'having a head extending outwardly from the externalsuri'ace of the body at vone end and a reduced stem at the other end adapted to be secured in said opening, there being ashoulder lon the body extendinginwardly from the external surface of the body at the root oi' the stem for -engaging said face to definitely space the head with respect to said face, a Asleeve member installable over said shoulder 'and supported on the body between said face and head for free relative rotation, the rsleeve having a lateral fluid opening, the body having a fluid passage extending between and connecting said openings. and

to prevent the leakage of fluid from therebetween.

4. A swing joint for use with. a part having a fluid opening and a face, the joint comprising a body formed for screw threaded attachment to said part and having a shoulder extending inwardly from the external surface of the body for cooperating .with said face to deilnltely limit the screwing of the body to said part, the bodyI having a second shoulder extending outwardly from the external surface of the body and spaced from and opposing said face, a member installable over the first. named shoulder surrounding the body between said face and second shoulder and vrelated to the body for relative rotation, the cooperation of the first named shoulder and said face preventing the member from being clamped between said face and second shoulder, themember having a lateral fluid opening, the body hav-v ing a uid passage extending between and connecting said openings, and means for sealing between the body and member at opposite sides ofthe point of communication of thepassage with the second named opening.

5. A swing joint i'or use with a part having a iiuid opening and a face, the joint comprising two elements related for free relative rotation. one a body having two longitudinally spaced correspondingly facing shoulders, the other a sleeve rotatably supported on the body, a stem on the body adapted to be secured in said opening, one

of said shoulders extending inwardly from the external surface of the body and the other shoulder extending outwardly from the external surface of the body, the first named shoulder Aserving to engage said face to definitely space the otherlshoulder from said face, the sleeve,

vinstallable over the iirst named shoulder, being arranged on the body between said face and said other shoulder and having a lateral iluid opening, the body having a fluid passage extending between and connecting said openings, one oi the elements having a groove spaced from each side oi' said lateral opening, and sealing rings in said grooves for sealing between the body and sleeve to prevent the leakage of fluid from therebetween.

8. A swing joint for use with a part having a fluid opening and a face, the joint-comprising two elements related for free relative rotation, one a body having two longitudinally spaced correspondingly facing shoulders, the other a sleeve rotatably supported on the body, a stem on the body adapted to'be secured in said opening, one of said shoulders extending inwardly from thel external surface of the body and the other.

vshoulder extending outwardly from the external surface of the body, the nrst ynamed shoulder serving to engage said face to definitely space the other shoulder from said face, the sleeve, installable over the nrst named shoulder, being arranged on the body between said face and said other shoulder and having a lateral iluid opening, the body having a iluld passage extending between and connecting said'openings, one of the elements having a groove spaced from each side of said lateral, opening, and. sealing rings oi cylindrical transverse cross section in said grooves for sealing between the body and sleeve to prevent the leakage of nuid from therebetween.

' G. SHEPHERD 

